Comparison between Malassezia Folliculitis and Non-Malassezia Folliculitis

BACKGROUND: Among the various types of folliculitis, differentiation of Malassezia folliculitis (MF) from other forms of folliculitis is important because it is usually treated with antifungal agents. OBJECTIVE: We attempted to find a method to enhance the detection rate of MF, and examined the differences in the clinical manifestation between MF and non-MF (NMF). METHODS: We performed a retrospective study involving patients with folliculitis who were previously diagnosed with MF or NMF on the basis of serial tissue sectioning and diastase-Periodic acid-Schiff (d-PAS) staining findings. The clinical features of MF and NMF were compared. RESULTS: Among a total of 100 folliculitis patients, 20 were diagnosed with MF and 80 with NMF. Tissues from the 80 patients with NMF were sectioned serially into 10 slices and stained with hematoxylin and eosin stain; among these, 10 had many round-to-oval yeast organisms in the hair follicles that confirmed MF. Finally, d-PAS staining was used to detect the presence of yeast in the NMF slides. Notably, among the 70 d-PAS-stained samples, yeast organisms were found in 6 samples, confirming MF. As a result, the diagnosis of 16 patients changed from NMF to MF. Compared with NMF, MF showed major involvement of the trunk and low involvement of the face and legs as well as male predilection. CONCLUSION: Physicians should consider serial sectioning and/or d-PAS staining of folliculitis lesions, particularly of those on the trunk of male patients, even if no yeast organisms are detected initially.

Development of the respiratory system serial section study of 6 and 12 mm rat and 10 mm pig embryos.

The human lower respiratory system begins to form about day 26-27 after conception, and is first indicated by a median larngotracheal groove in the caudal and of the ventral wall of the larynx, trachea, bronchi and the pulmonary lining epithelium. The connective tissue, the cartilage and the smooth muscle of these structures develop from the splanchnic mesoderm surrounding the foregut. In studying the development of the respiratory system at the Department of Anatomy, Siriraj Hospital, Medical students should trace the serial section of 10 mm and 15 mm pig embryos. In doing this, they be able to observe the layngotracheal groove at the floor of the pharynx and when, tracing the sections caudally, they will be able to observe the trachea, esophagus and the bifurcation of the trachea to from primary bronchi as well as the smaller branches of bronchi. The present study attempts to show the development of the respiratory system of rat embryos in order to find the most suitable stage which can be used as a laboratory model for use by students. A 6 mm rat embryo can be used instead of a pig embryo for studying the development of the respiratory system, if pig embryos are not available.